The consumption of thermoplastic resins like ABS and ASA resins is rising sharply in the fields of household, interior materials of car, office equipments, building materials, etc. Recently, the demand for nongloss resin to create elegant atmosphere is rising as consumers' sensitivity levels are going up. In addition, considering environmental problems, an effort has been made to exclude the processes of nonglare painting or pading, and to directly use nongloss resin instead.
For matting effect, the domain of roughness of resin surface is expanded over the range of visible ray to disperse incident light, and the following three methods are generally used.
These methods are mainly based on the method to improve the properties of acrylonitrile-butadiene-styrene resin. The first method is to use large size rubber particles more than 2 μm in diameter obtained from bulk polymerization, and the second method is to add nongloss filler whose particle size is over 5 an to resin. The third method is that monomers such as ethylene-unsaturated carboxylic acid are grafted as a modifier to acrylonitrile-butadiene-styrene copolymer prepared by emulsion polymerization.
However, the first method cannot guarantee low-gloss effect, and the decreases of impact strength and heat deflection temperature are also problems even when it shows low-gloss effect. Resin created by the second method shows excellent plasticity, but weakness in low-gloss and particularly in impact strength. The third method has been widely used to enhance non-gloss effect of resin since the resin produced by this method shows excellent low-gloss and good physical properties and increased impact strength. But, it also requires processing devices such as polymerization facilities, in addition to high cost owing to the great process-dependency.
The present inventors tried every effort to overcome the above problems and at last completed this invention by confirming that thermoplastic resin composition having enhanced workability and impact strength together with reduced gloss can be produced by simply adding low-gloss additive.